Medical devices such as endovascular or intravascular devices have been used for many years for purposes such as performing medical procedures, including treating aneurysms. A medical device such as an intravascular device may be introduced into a patient's anatomy or vasculature at a relatively accessible location, and guided through the patient's anatomy to the desired location. X-ray fluoroscopy has been used to observe the tip of the medical device and the device has been rotated at bifurcations in the anatomy or vasculature before being pushed further to guide the device to the desired location. Medical devices of this type may be solid, for example, a guide wire, or may be hollow and tubular, for example, a catheter. Guide wires may be used to guide one or more tubular intravascular devices to a particular location, and catheters may be used, for instance, to deliver fluids, extract fluids, or deliver various objects, agents, or devices to the particular location.
In many applications it is desirable that a medical device or intravascular device bend easily in order to allow it to make the various bends and turns that are necessary to navigate through the anatomy or vasculature, and in some cases also to minimize trauma to the anatomy or vasculature. However, in many applications it is desirable that the medical device be relatively stiff in torsion in order to allow precise control of rotation in order to guide the device through bifurcations in vasculature or around obstacles. Accordingly, medical and intravascular devices have been described that contain numerous cuts along their length to obtain the desired flexibility in bending while maintaining relative stiffness in torsion. Examples of such devices are described in U.S. Pat. Nos. 5,690,120 and 5,833,632, both of which are incorporated herein by reference in their entirety. An example of a method of making such devices is described in U.S. Pat. No. 6,260,485 B1, which is also incorporated herein by reference in its entirety.
In many applications, it is desirable that the tip of a medical device be soft and bendable so as to minimize trauma to the patient's anatomy and further facilitate negotiating bends and turns in the anatomy or vasculature. Thus, a need exists for such a soft and bendable tip. In addition, the tip of a medical device may be bent or curved so that when the device approaches a bifurcation, or other location where direction needs to be selected, the device may be steered in the correct direction. In the past, tips were bent or curved during initial fabrication of the device. However, in at least some applications, a greater or lesser curvature may be desirable. Accordingly, a need exists for a device wherein the angle or radius of bending or curvature of the tip may be selected by the operator of the medical device, for instance, by the medical doctor performing a medical procedure with the medical device.
Furthermore, in many applications, it is desirable and important that the entire device be removed after the procedure is completed. Thus, it is desirable that the device have a strong and reliable tensile strength throughout its length so that it does not come apart when pulled out of the patient's anatomy or vasculature. Accordingly, a need exists to improve and provide redundancy in the tensile strength of a medical device to assure complete removal of the device.